Process for the production of carbon monoxide



li e-tented duly ll, i929.

last-v llE lttU UEEaEl FUR- lI'I-TE PROJDUGETIUN OF CARBON IVIONUITJUDIE.

in; namin This invention relates to the production or carbon monoxide from mixtures of carbon dioxide and hydrogen, and pertains more specifically to the product-ion of carbon mon- 5 oxide from the mixture of gases evolved during the butyl-acetonic fermentation of carbohydrates.

' in the manufacture of butyl alcohol and acetone by the fermentation of carbohydrate to materials there is evolved a gas containing approximately of hydrogen and 55% of carbon dioxide, both by volume. Elmall amounts of butyl alcohol, ethyl alcohol, and acetone may also be present in the gaseous 35 mixture due to entrainment of the solvents from the fermenting mash during gas evolution.

The principal object of my invention is to provide a process for the production of carhon monoxide in pure to'rm from various gas mixtures of hydrogen and carbon dioxide,

particularly from butyl fermentation gases. Uther objects of my process and invention will become apparent.

l l hile term enter gases-perse-may be employed in my process, in the case of fermenter gases it is advisable, for the sake of economy,

to first remove the volatile solvents. These solvent vapors may be readily removed "fromthe gaseous mixture by passing the gases through suitable scrubbing towers or absorbing towers such as are well known and lunch used in the art.

To produce pure carbon monoxide from termenter gases in accordance with my invention and process, it is necessary to adj ust-the rela-v tive quantities of carbon dioxide and hydrogen in the termenter gas so that the two substances are present 1n molecular proportions and may combine according to the following chemical equation: 7

@0,+H =UO +11 0 58 pound of hydrogen, Whereas, fermenter gas,

per se, contains about twenty'six pounds of carbon dioxide tor each pound of hydrogen. Accordingly, it pure carbon monoxide is to be prepared from the mixture without leaving. residuum of carbon dioxid c, it is necessary Application filed April 27/, 19%. Serial No. 26,305.

to remove some carbon dioxide from the termenter gas before the reaction occurs.

The gaseous mixture may, in any event bereadily adjusted to the proper ratio oi carbon dioxide and hydrogen by passing the gaseous mixture through, or in contact with pure water at elevated pressures which will dissolve the excess carbon dioxide and may also serve to absorb solvent vapors at the same time.

l erinenter gas, in its original state, or modified in its carbon dioxide content so as to secure an exact ratio of carbon dioxide and hydrogen, is suitable for employment in my process for the production ot. carbon mouoxide.

Tn accordance with my invention and process, the gaseous mixture is passed into a heated zone whereupon at ce tain temperatures the carbon dioxide and hydrogen react to form water and carbon monoxide in accord ance with the following equation UU HF UU Him the temperature rises. At 1000 C.,l[t=0.234-

and the gas mixture contains about 16.3% of carbon monoxide.

While a temperature higher than 1000 U will produce a gas mixture which, at equilibrium, will contain more than 16.8% of car bon monoxide, ll prefer to employ temperatures of the range 1000-1200 and to enrich the as mixture with carbon monoxide by disturbing the equilibrium of the reversible reaction hitherto indicated.

This equilibrium may be disturbed by removing the water vapor as fast as it is formed in the'reaction. As the water isremoved, the reaction equilibrium is disturbed, and more and more carbon monoxide is formed.

Thus, in accordance with my invention it is possible to prepare gaseous mixtures which may contain -from 16% to oi carbon monoxide by alternately heating and cooling the gaseous mixture. This alternate heating and cooling must occur in re id succession to be etl'ective tor unless 'lll tlll

tltl

lOU

lUtl

rapid temperature changes are effected, par

ticularly on cooling, the equilibrium will be disturbed and some of the previously formed carbon monoxide and water will react again to form carbon dloxide and hydrogen.

I have discovered, iurther, that, the reaction of carbon dioxide and hydrogen to form carbon monoxide is accelerated by certain catalyticagents, notably by metals, their oxides,

and carbonates. In general, however, any by drogenation catalyst is suitable and this may be employed in conjunction with a"promoter which stimulates, andincreases the catalyst activity. For example, combinations of iron promoted by uranium, or cerium oxide "promoted by thorium oxide are suitable.

These catalysts are employed bysimple con tact with the gaseous mixture.

The rapid alternate heating and cooling of the gasmay be accomplished in various types of apparatus. For example, the gaseous mixture may be passed through an apparatus or tube containing a multiplicity ofhe'atingf elements-and cooling elements against which the gaseous mixture alternately impinges. At each heating element some carbon monoxide is formed, and at each cooling element some water is condensed and removed, whereby the equilibrium is disturbed, so that at the next contact with heatmore carbon monoxide is formed. A suitable apparatus for the -.perforinance of the process is described in my co-pending application, Serial N6. 28,350, filed May 6th, 1925. However my.

invention and process is not dependent on any specific type of apparatus.

Now, having fully described my invention, I claim the following as new and novel 1. A process forthe production of carbon monoxide which consists in rapidly heating the gas evolved from the butyl-acetonic fermentation of'carbohydrates to about 1000- 1'200 0., rapidly cooling the gaseous mixture to below 100 C. whereby the water formed in the reaction is condensed, removing the condensed water and continuing rapidly the alternate heating and cooling of the gaseous mixture for the further pro duction of carbon monoxide.

3. A process for the production of carbon monoxide which consists in rapidly heating a gaseous mixture containing approximately twenty-two pounds of carbon dioxide per pound of hydrogen to about 1000-1200 (3., rapidly cooling the gaseous mixture to below 100 C. whereby the water formed in the re action is condensed, and removing the condensed water.

4. A process for the production of carbon monoxide which consists in rapidly heating a gaseous mixture containing approximately twenty-two pounds of carbon dioxide per pound of hydrogen to about 1000-1200 (7., rapidly cooling the gaseous mixture to below 100 0. whereby the water formed in the reactionis condensed, removing the condensed waterjand continuing rapidly the alternate heating and cooling of the gaseous mixture rapidly cooling the gaseous mixtureto below- 100 (1. removing the condensed water, and

continuing rapidly the alternate heating and cooling of the gaseous mixture for the further production of carbon monoxide.

In testimony whereof I afiix my signature.

WILLIAM C. ARSEM. 

